PANNICULITIC GAMMA DELTA T-CELL LYMPHOMA WITH CONCOMITANT FEATURES OF AUTOIMMUNE DISEASE EMPHASIZING A PATHOPHYSIOLOGIC CONTINUUM WITH THE PANNICULITIC T CELL LYMPHOMAS.

There are T-cell lymphomas, which exhibit unique homing properties of the neoplastic lymphocytes for the subcutaneous fat. Primary cutaneous gamma delta T-cell lymphomas of the fat (PGD-TCL) typically have an aggressive clinical course; the more indolent variant is subcutaneous panniculitis like T-cell lymphoma (SPTCL), comprising T-cells of the alpha beta subset. These t wo forms of subcutaneous T-cell neoplasms exhibit many overlapping histologic features with lupus profundus (LP); it has been previously suggested by one of the authors that lupus profundus is a form of a panniculitic T-cell dyscrasia. We present three cases of PGD-TCL of the fat in the setting of lupus erythematosus (LE) (two cases) and dermatomyositis (DM) (one case), respectively, whereby there were concurrent features of LE and DM in their lymphoma biopsies in 2 cases and prior biopsies compatible with LP which presaged the diagnosis of PGD-TCL by 3 years during which time the patient had a positive response to Plaquenil.